The present invention relates to an image sensor and, more particularly, to an image sensor which detects reflected light from an original image using photoelectric converters and generates image signals, and an image processing apparatus using the image sensor.
FIG. 10 is a cross-sectional view showing a configuration of a conventional image sensor of the aforesaid type. Referring to FIG. 10, the image sensor is basically configured with a sensor array 1 composed of a sensor substrate 101 and sensor ICs 102 mounted on the sensor substrate 101, an lens array 2, an illumination device 3 for illuminating an original image, a cover glass 4, and a frame 5 for holding the foregoing elements and devices at fixed positions.
The lens array 2 is formed by arranging a plurality of rod lens elements, each of which functions as a lens by graduating index of refraction from the peripheral portion toward the central portion of the lens element, in a line. The lens array 2 propagates reflected light from the original image and forms an image on the sensor ICs 102. An imaging area on the sensor substrate 101 is shown in detail in FIG. 11. In FIG. 11, X0 denotes the radius of the imaging area. Since imaging areas of the lens elements having radius X0 overlap to each other, although it is not shown in FIG. 11, the overall imaging area of the lens array 2 on the sensor substrate 101 has a band shape whose width is X (=2xc3x97X0).
As shown in FIGS. 10 and 11, the sensor IC 102 is electrically connected with the sensor substrate 101 via an electric connection portion 104 and a conductive thin wire 103. Further, the surface of the electrical connection portion 104 of the sensor substrate 101 is formed with metals, such as gold and silver, and the portion 104 is formed within the imaging area of the lens array 2.
However, the reflectivity of metals, such as gold and silver, forming the electrical connection portion 104 on the sensor substrate 101 of the aforesaid conventional image sensor is high. Accordingly, when light propagated through the lens arrays 2 incidents on the electrical connection portion 104, the light is mostly reflected by the metal and becomes stray light. As a result, there is a problem in which the stray light incidents on photo-sensing portions of the sensor ICs 102 as light noise, which causes deterioration of the S/N ratio of sensor output.
The present invention has been made in consideration of the above situation, and has as its object to provide an image sensor whose S/N ratio is improved.
According to the present invention, the foregoing object is attained by providing an image sensor comprising: signal generation means for generating an image signal on the basis of reflected light using a plurality of photoelectric converters arranged on a substrate; and image forming means for projecting the reflected light, from an original image, within a predetermined area on the substrate on which the signal generation means is provided, wherein the signal generation means includes signal output portions for outputting the image signal from the plurality of photoelectric converters to the outside of the signal generation means, and a part or all of the signal output portions is arranged outside of the predetermined area on the substrate.
With the present invention as described above, since incoming light does not incident on electrodes on the sensor substrate, no light is reflected by the electrodes, thereby no noise light incidents on a photoelectric converter.
It is another object of the present invention to provide a down-sized and down-weighed image sensor.
According to the present invention, the foregoing object is attained by providing the image sensor comprising aperture stop for reducing the diameter of the imaging area of the lens.
With the present invention as described above, mounting density of the photoelectric converters and electrodes on the sensor substrate can be increased.
It is another object of the present invention to provide an image processing apparatus capable of performing high quality scanning of an image.
According to the present invention, the foregoing object is attained by providing an image processing apparatus comprising: original feeding means for feeding an original image; reading means for reading the original image using an image sensor and generating image signals; print medium feeding means for feeding a print medium; and print means for printing an image on the print medium on the basis of the image signals read by the reading means, wherein the image sensor used in the reading means comprises: signal generation means for generating an image signal on the basis of light information using a plurality of photoelectric converters arranged on a substrate; and image forming means for projecting the light information, from the original image, within a predetermined area on the substrate on which the signal generation means is provided, wherein the signal generation means includes signal output portions for outputting the image signal from the plurality of photoelectric converters to the outside of the signal generation means, and a part or all of the signal output portions is arranged outside of the predetermined area on the substrate.
With the present invention as described above, it is possible to install an image sensor having a good S/N ratio of sensor output to an image processing apparatus.
The invention is particularly advantageous since the S/N ratio of the output from the image sensor is improved and it is possible to provide an image sensor and an image processing apparatus capable of performing high-quality scanning of an image.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.